On 05/31/2018 10:59 AM, Jesper Dangaard Brouer wrote:
> When passed the XDP_XMIT_FLUSH flag ixgbe_xdp_xmit now performs the
> same kind of ring tail update as in ixgbe_xdp_flush. The update tail
> code in ixgbe_xdp_flush is generalized and shared with ixgbe_xdp_xmit.
>
> Signed-off-by: Jesper Dangaard Brouer <bro...@redhat.com>
> ---
> drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 20 ++++++++++++++------
> 1 file changed, 14 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> index 87f088f4af52..4fd77c9067f2 100644
> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> @@ -10022,6 +10022,15 @@ static int ixgbe_xdp(struct net_device *dev, struct
> netdev_bpf *xdp)
> }
> }
>
> +static void ixgbe_xdp_ring_update_tail(struct ixgbe_ring *ring)
> +{
> + /* Force memory writes to complete before letting h/w know there
> + * are new descriptors to fetch.
> + */
> + wmb();
> + writel(ring->next_to_use, ring->tail);
> +}
Did you double check that this doesn't become a function call? Should this
get an __always_inline attribute?
> +
> static int ixgbe_xdp_xmit(struct net_device *dev, int n,
> struct xdp_frame **frames, u32 flags)
> {
> @@ -10033,7 +10042,7 @@ static int ixgbe_xdp_xmit(struct net_device *dev, int
> n,
> if (unlikely(test_bit(__IXGBE_DOWN, &adapter->state)))
> return -ENETDOWN;
>
> - if (unlikely(flags & ~XDP_XMIT_FLAGS_NONE))
> + if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
> return -EINVAL;
>
> /* During program transitions its possible adapter->xdp_prog is assigned
> @@ -10054,6 +10063,9 @@ static int ixgbe_xdp_xmit(struct net_device *dev, int
> n,
> }
> }
>
> + if (unlikely(flags & XDP_XMIT_FLUSH))
> + ixgbe_xdp_ring_update_tail(ring);
> +
> return n - drops;
> }
>
> @@ -10072,11 +10084,7 @@ static void ixgbe_xdp_flush(struct net_device *dev)
> if (unlikely(!ring))
> return;
>
> - /* Force memory writes to complete before letting h/w know there
> - * are new descriptors to fetch.
> - */
> - wmb();
> - writel(ring->next_to_use, ring->tail);
> + ixgbe_xdp_ring_update_tail(ring);
>
> return;
> }
>
